Decisions to implement insecticide treatments should be based on detection of the pest and/or damage occurrence, and not on a scheduled, preventative insecticide-based treatment regime. More often than not, the occurrence of damaging levels of insect pests is an indication of a more basic agronomic problem (mismanagement of fertility, watering, site selection practices) that, if corrected, will prevent further outbreaks of these "secondary" pests. However, even when sound agronomic practices are closely followed, a probability of pest outbreaks exists. When outbreaks do occur, effective methods of suppressing damaging population levels must be implemented.

Table 1. The approximate seasonal occurrence of major arthropod pests on turf in the coastal regions of Texas (XXXX's indicating the period of peak occurrence and possible treatment periods).

Armyworms: Treat when large numbers of worms are present and damage is becoming excessive (carbaryl, chlorpyrifos, diazinon, malathion, methoxychlor and trichlorfon)(See L-1725).

White grubs (immature June beetles): Examine turf during the suggested treatment period. Treatment is justified when more than 4 grubs per 1 ft (4 inches deep) per 1000 ft2 of lawn are found (chlorpyrifos, diazinon, isofenphos)(See L-1131).

Chinch bugs: Treatment should be initiated at first signs of damage when chinch bug populations are present (carbophenthion, diazinon, ethion, chlorpyrifos and others)(See L-1766).

Crickets (Field crickets, mole crickets): Treat when annoying populations exist and damage becomes evident (chlorpyrifos, diazinon, malathion, propoxur, resmethrin, carbaryl bait, metaldehyde bait)(See L-1809).

Mites (Banks grass mite, bermudagrass stunt mite): Treat when mites are present and causing damage (diazinon, dicofol, ethion, sulfur)(See L-1244).

Fire ants: Treat when mound or ant activity interfere with turf usage, using the best combination of tactics to achieve management objectives (acephate, avermectin, bendiocarb, carbaryl, chlorpyrifos, diazinon, fenoxycarb , hydramethylnon, isofenphos, methyl chloroform, permethrin, Prodrone rotenone)(See B-1536).

Fleas: Treat as part of a total flea management program that includes treatment of household, pets and yard (bendiocarb, carbaryl, chlorpyrifos, diazinon, malathion, propoxur, ronnel, gynergized pyrethring)(See L-1738).

Ticks: Treat when ticks become numerous (chlorpyrifos, diazinon, propoxur, carbaryl)(See L-1403).

Chiggers: Use repellents in infested areas. Use insecticide applications to suppress bothersome infestations when they occur (chlorpyrifos, diazinon)(See L-1223).

Note: Other pests associated with turf that may require management include clover mites (See L-2040), ground-dwelling wasps, hornets or bees (See L-1828), centipedes and millipedes (See L-1747), Texas leaf cutting ants (See L-1222) earthworms and crawfish.

PLANNING YOUR PEST MANAGEMENT ON ORNAMENTAL TREES AND SHRUBS

When establishing new landscapes, select low maintenance, environmentally adopted, pest free species. Euonymus and Virginia pines are good examples of plants that will be pest infested unless continually treated with insecticides. Once established, practice sound horticultural methods to reduce plant stress and maintain vigor (don't under-fertilize). Plants in good condition will be less attractive to pests and can better tolerate damage. Conversely, do not over-fertilize, since this practice can make plants more attractive to certain pests such as aphids due to lush growth.

Because the ornamental landscape is composed of a combination of different species and varieties of plants, designing a single management program for the entire landscape is extremely difficult. Each species has its own requirements for maintaining plant health, and each has its own level of tolerance to arthropod damage before its health and/or aesthetic value is threatened. First, determine your goals for management. Decide what level(s) of damage can be tolerated prior to taking action to suppress pest populations. In general, little or no damage can be tolerated on plants produced for sale, or highly valued plants in prominent positions in the landscape, whereas plants in a landscape maintenance program can sustain some damage from pests before their health and/or aesthetic value becomes impaired.

Pest suppression tactics are best implemented when the pests causing sufficient damage (or threaten to cause sufficient damage) first appear. Take action during the most vulnerable life stage(s) of the pests. Monitor pest populations using 1) visual inspections of randomly selected sets of leaves, 2) the beat method where pests are dislodged from their host plants by beating plant parts on a piece of paper (this method is great for detecting mites, thrips and scale crawlers), 3) using yellow sticky traps to attract winged aphids, thrips, whiteflies, fungus gnats and shore flies (this method is best suited to the greenhouse), 4) Black light traps and 5) pheromone traps. Remember that the presence of the pest is not justification for treatment, Inspect plants to determine that the pest is beginning to cause a sufficient amount of plant damage prior to treatment.

For some pests, notably scale, aphids and phylloxera, management begins during the winter when dormant oil is applied prior to the swelling of the buds. On evergreen plants, use a lighter (summer) oil or check the label to ensure that application of the oil will not result in plant injury (phytotoxicity). Selection of pesticides for the suppression pests on ornamental plants is extremely important since some species/ varieties/cultivars are extremely sensitive to them. Follow the label directions and use on plants listed there. If the label is general (ie. "use on ornamentals") always test pesticides on a few of the plants and observe any phytotoxic reactions that may develop prior to treating all the plants.

Practice good sanitation in the landscape, removing dead limbs, dead leaves (particularly those harboring insect-caused galls), and remove hiding places for "trash pests" such as millipedes, sowbugs, pillbugs, snails and slugs. During the "off season", repair and maintain equipment and update your pesticide product label and material safety data sheet file by contacting chemical company representatives or attending trade shows. Don't depend solely on your memory to remember label instructions and rates. Labels change over time (ie. see a lindane label).

Table 2. The approximate seasonal occurrence of major arthropod pests on ornamentals in the coastal regions of Texas (XXXX's indicating the period of peak occurrence and possible treatment periods).

Aphids: Many species of aphids exist and they affect most ornamentals. High populations of some species build up during winter months on evergreens or bedding plants and populations build up rapidly on new growth in the spring. Some species, such as wooly aphids, are favored by hot dry weather (acephate, diazinon, dimethoate, malathion, oxydemeton-methyl, synergized pyrethroids, pyrethrins, disulfoton, insecticidal soaps, dormant oil)(See L-1227).

Scales: Like aphids, species are numerous and biologies differ. Generally, control includes applying dormant oil and insecticide treatments timed to correspond to the hatching of scale eggs and the appearance of the crawler stages. Control may require 2 to 4 applications at 7 to 10 day intervals (dimethoate, acephate, disulfoton, oxydemeton-methyl are systemics and pyrethrins, resmethrin, dichlorvos, malathion, azinphosmethyl, diazinon and chlorpyrifos are contact insecticides)(See L-1827).

Bagworms: Hand-pick bags in the winter to eliminate spring populations. If impractical, treat in spring when new bags are less than 1/2 inch long (carbarly, chlorpyrifos, trichlorfon, diazinon, acephate, Bacillus thuringiensis or malathion)(See L-1802).

Cankerworms: If practical, prevent wingless females from depositing eggs in the fall by placing a band of stick material around the base of the tree 3 to 4 feet from the soil. Otherwise, treat less than lt2-grown larvae in the spring when damage is beginning to appear (malathion, carbaryl, acephate, methoxychlor, Bacillus thuringiensis)(See L-1829).

Tent caterpillars Eastern, Western, Forest and Sonoran): Inspect trees for egg masses in the winter and remove them, if practical. After eggs hatch and tents appear, prune nests from trees and/or destroy them or spot treat if feasible (diazinon, Bacillus thuringiensis, carbaryl, malathion, methoxychlor)(See L-1637).

Fall webworms: There are 2 to 4 generations per year. In winter and early spring, egg masses and webs can be removed and/or destroyed if practical. Otherwise, webs can be spot-treated or plants can be sprayed when webs are numerous and worms are not not fully grown (acephate, Bacillus thuringiensis, carbaryl, diazinon, malathion, chlorpyrifos, methoxychlor or trichlorfon)(See L-1811).

Walnut caterpillars: There are 2 to 3 generations per year in Texas, with the last one being the most damaging. Monitor for egg deposits and hatch on the undersides of leaves and treat if small worms are numerous (carbaryl, malathion, diazinon, acephate, methoxychlor, trichlorfon or Bacillus thuringiensis)(See L-1835).

Lacebugs: Populations begin to build up in early spring. If feasible, wash off nymphal populations. Otherwise treat when damage becomes evident on highlyvalued ornamentals (dimethoate, malathion, acephate, carbarly on 10-14 day intervals until control is achieved)(See L-1739).

Elm leaf beetles: Check undersides of leaves for yellow eggs and young larvae in March or April. If present treat 3 weeks after leaves have emerged and again in 2 to 3 weeks. Continue to monitor at 2 to 3 week intervals throughout the summer and treat if reinfestation occurs (carbaryl, methoxychlor, acephate)(See L-1812).

Borer beetles (Roundheaded, flatheaded, and caterpillars; many species): Maintain tree health to make trees less attractive to borer beetles. Practice proper pruning and use wound paint during the summer months. To protect highly-valued or stressed trees use trunk wrapping or chemically treat regularly at 3 to 5 week intervals throughout the summer unless the biology of the borer 6pecies involved i9 known (chlorpyrifos, lindane). Remove worms present using a knife or other implement or treat individual exit holes with insecticide if practical (See L-1004).

Twig girdlers (Genus Onciders, three species): Remove and/or destroy girdled limbs in fall or protect small highly-valued damage-proned trees during the fall with insecticide treatments applied at 3 to 5 week intervals (chlorpyrifos) until trees lose their leaves (See L-1004).

Mites: Outbreaks occur anytime during the year, particularly during dry months or following use of certain broad-spectrum insecticides. Treat when mites are present and damage becomes noticeable (acephate, chlorpyrifos, diazinon, dicofol, disulfoton, ethion, malathion, oxydemeton-methyl pyrethrins, sulfur, dormant or summer oils, or insecticidal soaps)(See L1244).

Suggested pesticides must be registered and labeled for use by the Environmental Protection Agency and the Texas Department of Agriculture. The status of pesticide label clearances is subject to change and may have changed since this publication was printed.

The USER is always responsible for the effects of pesticide residues on his livestock and crops, as well as problems that could arise from drift or movement of the pesticide from his property to that of others. Always read and follow carefully the instructions on the container label.

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The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Cooperative Extension Service is implied.

Educational programs conducted by the Texas Agricultural Extension Service are open to all people without regard to race, color, sex, disability, religion, age or national origin.

1988

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Last modified: March 18, 1997 by Edgar Cross